Yeap, I am designing an Axon II. The design is almost complete, but wanted some input before I finish it up and make some prototypes. Feel free to suggest here!

Major changes made from the original Axon:2x more PWM2x more external interruptsmuch faster, more stable regulated power distributionfour additional I/Ofour fewer servos (no one needed more than 20 so far)green number displayexternal memory supportlots of various little improvements

With the exception of pinout, the source code is 100% compatible with the previous Axon. Dimensions are exactly the same, too. Price might go down $5, but no promises yet until I get some quotes.

Is there a particular reason why the 1280 or 2560 is not going to be used? Is the 640 already overkill for most projects?

The 640 has 64KB, but my largest Axon program didn't exceed ~40kb with optimization turned off. No one has reported running out of memory. The 1280 is about the same price of the 2560. The 2560 costs about $5 more each, so lets say I make 1000 units, it'll cost me $5k for memory no one will even use

My current (ambitious) design is looking to use at least 33 servos, 13 sensors, and 1 camera >.>Guess I'll need sub micro-controllers to distribute servo load, though I was looking at doing that already for power distribution reasons.

I think you should make an Axon-like board with a PIC32MX460F512L instead. The current Axon is pretty much a massive MCU board designed for servos and sensors with a USB to serial converter and power regulation, so why not upgrade it with a better processor that costs less? You'll save even more money by not having that USB to serial converter since the PIC32 has USB OTG.

Have a look at UBW32 http://www.sparkfun.com/commerce/product_info.php?products_id=8971It should be easy to make an Axon design with the same chip. I'm surprised people don't just solder that to another board with some headers for a robotics board, sure it won't look nice that way, but it'll save $90, minus maybe $20 for a perf-board and power supply parts. You'll still have enough money to get a PICKit2 if you didn't already own one.

Sure, it's overkill, but you are charging $130 for the Axon already. I'm sure most of that isn't associated with part costs, and the ATmega640 is about $12 while the PIC32MX460F512L costs about $8 according to Octopart, so why not? Your manufacturing costs should be the same and your part costs should be lower.

I'm working on an ATmega644 based quadrotor helicopter right now and an major concern has been processor speed due to the trigonometry and filtering functions, the trig has been sped up by using a look-up table in flash, but the filtering is still slow due to the floating point operations. I think a speed boost would be great, and the 32 bit processor running at 80 MHz would really be great for math intensive robotics projects like mine.

You might argue that AVR has more open source tools, but as I work into more complicated stuff, the more I feel the limitations of the free AVR-GCC compiler. The student editions of Microchip's C compilers are free and have great code support too. The PICKit2 is better than an AVR Dragon for about half the cost, although you can always ship the PIC32 with the USB bootloader.

You'll have one less UART and less PWM, and have 5x 16 bit timers instead of 4x 16 bit and 2x 8 bit, but there's two I2C busses, and the UART has autobaud support

Also the cost for Admin to write whole new source code, and he has to pay for the time for testing the new MCU. He said that the main cost of the Axon was the time put in to design and testing to get it to work just right.

Depends on Atmel's stock and how fast I sell the original. Probably won't come out sooner.

frank26080115, appears its better by the faster processor and built in USB. The disadvantage is that I'd have to relearn a new architecture, rewrite all my tutorials and software, make a new bootloader, and make an extra prototype or two until I figure it out. With the Axon you aren't just buying hardware, but also ready to use software and tutorials and forum support to get a beginner started within hours. That sparkfun link only offers datasheets and schematics, its not plug-n-play at the least . . . That being said, Atmel better get some USB in their ATmegas or they'll lose customers . . .

You are targeting a $130 product towards beginners? I thought your target market is competent builders who simply need a powerful prototyping platform. I feel somebody who needs all those IOs and peripherals is going to find the slow speed a real bottleneck someday.

How about sticking a microSD card holder on it? Using Tiny-FatFs is really easy.

You are targeting a $130 product towards beginners? I thought your target market is competent builders who simply need a powerful prototyping platform. I feel somebody who needs all those IOs and peripherals is going to find the slow speed a real bottleneck someday.

How about sticking a microSD card holder on it? Using Tiny-FatFs is really easy.

Yeap, and it sells great too I think your quadrotor is an exception, have you considered not using floating point? I multiple everything by 10 or 100 to avoid it. I agree with you that the PIC32MX460F512L appears better (on glance), but it'd require me to learn a new architecture and ditch the current Axon community.

You are the second person to mention the SSD card option, but I decided too small a percentage of people would find a use for it.

Oh and it's only a little more than $1 cheaper (at the quantity that I purchase).

Looks like the 7 segment LED replaces the status LED from the original Axon. Kind of a waste to use 7 pins on it but I doubt anyone will miss those.

Yea I don't think anyone needs more than 58 I/O, and it only costs me ~$1.60 to add it. It uses pins that people wouldn't normally want for anything. It was actually Dunks idea.

offy, SmAsH, it can display any number you want, to represent anything you want. For example, it can display a sensor value, or represent what code it's running at the time. Or perhaps be used as a timer. Or use it to count the number of times you push a button (to specify some value).

I have moved to integer math, everything is multiplied by 10000 since the filter needs delta time and that can differ by 1/10th of a millisecond. Each loop took around 3-6ms using floating point and now it takes 1.1 to 2.3ms.

I think I can agree now that it is probably a better decision for you to keep using AVR, but I'd still rather see an inexpensive and powerful 32 bit board designed with focus towards robotics.

With a massive chip like that, somebody might want to do some on-chip debugging, have you thought about making JTAG easily accessible? It will be a pain in the butt to wire up the interface manually.

I've had cases when memory locations were accessed where they are not allocated, sometimes even into the stack, or the stack went too deep, and caused resets and other weird behaviour. Your hyperterminal will not let you analyze things like that in detail.

Nice looking...I agree with that JTAG think... I know many don't have a JTAG programmer and that's it's more expensive than ISP... But the quicker downloading (FLASH) and the on chip debugging is nice!If the JTAG pins are connected to normal IO then you could just ship a wire connector along to get a JTAG pad!!!Remember that JTAG doesn't need reset to operate... so it's a go go!

Logged

For whom the interrupts toll...

P.S. I've been inactive for almost a year... Don't give promises but I'll try to complete my tutorials. I'll let you know when..

I've had cases when memory locations were accessed where they are not allocated, sometimes even into the stack, or the stack went too deep, and caused resets and other weird behaviour. Your hyperterminal will not let you analyze things like that in detail.

Looks like the 7 segment LED replaces the status LED from the original Axon. Kind of a waste to use 7 pins on it but I doubt anyone will miss those.

Dont forget that the digital LED is made up of 8 independent LEDs (7 + 1 for the decimal point). So you effectively have 8 x status LEDs - obviously if you choose to make them look like a number then thats up to you. So its 'a bonus' - 8 leds that can also look like characters/digits.

2 x 8 segment displays would let you view 8 bit binary as hex for better debugging (00 to FF). You would have some trouble distinguising between 8 and B on the display but I think if there was an option for 2 then it definately be more useful than 1 8segment.

Maybe you could create an LCD standard rather than an inbuilt display. So you could purchase an optional display unit that is plug and play with supported software.

I know that 1 x 8segment display is better than none, but its really neither here nor there. Look at some graphical LCD's rather than just text ones (you might get some people creating a graphical api type software). with graphical displays you can see your maps live.

If you go down this route, and remove the 8 segment display, you might have room for the JTAG connector and also have additional sales through an add on unit.

Combine this with an addon unit for external memory; you just need an input device add on and your close to having a full user able system